Celebrities like Catherine Zeta-Jones don't always use expensive conditioners to get shiny strands—sometimes their go-to hair products are straight from the pantry: Though she admits it's a smelly process, Zeta-Jones often lavishes her brunette strands with beer to keep them sleek. Other popular Hollywood hair concoctions involve mayonnaise, egg yolks, vinegar, and olive oil, just to name a few.

Wary of adding kitchen staples to your shower routine? It's actually more practical than you might think. For example, beer is chock-full of B vitamins and, in particular, biotin—a nourishing ingredient also found in egg yolks, milk, and mayonnaise. Additionally, beer is packed with protein compounds which help rebuild, repair, and make hair shiny.

Olive oil is often used for its moisturizing benefits (try a hot olive oil hair mask over a store-bought one), while vinegar is great for removing residue build-up. For the benefits of both, plus a dose of protein and biotin, try regular mayonnaise: With vegetable oil, eggs, and vinegar in the mix, you can't go wrong. Add a few drops of vanilla extract to kill the stench, leave the solution on your hair for 15 to 20 minutes, and voila! Your deep-conditioning treatment is complete.